Modern automobiles are equipped with an impressive number and variety of sensors. The sheer number of sensors makes it desirable to minimize the wiring requirements of each sensor, subject to constraints on cost and reliability. Certain efforts in this direction have relegated error reporting to a secondary status, requiring the control unit to employ subsidiary modes to detect and report sensor errors. Such subsidiary modes generally require additional complexity as well as time that may not be available during many maneuvers.
For example, a parking-assist system may employ ultrasonic transducers or other parking-assist sensors (“PAS”) to monitor the distance between the vehicle and any obstacles in and around a selected parking spot. Due to environmental “noise” and safety concerns, the sensors may be asked to provide tens of measurements each second as the vehicle approaches and enters the confined area. With each measurement requiring roughly 20 milliseconds and each of the multiple transducers needing to be actuated in turn while the other transducers listen, at least some contemplated parking-assist systems will be unable to spare any time to switch to a subsidiary mode and query the status of the various sensors.